As a specific technology evolves and the related industry matures, the equipment used to implement the technology often converges toward a standard metric. That is, certain aspects of the equipment, such as the size of circuit packs, for example, or the type and layout of their connectors become standardized. In the telecommunications industry, strong efforts have been made toward standardization of equipment, including the development of a standard for circuit packs in certain companies. For example, at Lucent Technologies Inc., circuit packs comply with a OneNS height/depth/connector standards.
A circuit pack is an assemblage of various electronic and/or optical components which are mounted on a printed wiring board (PWB) with an edgeboard connector to allow it to interface with a PWB backplane. Usually, a backplane interconnects each circuit pack to other circuit packs, or to cables or both.
In general, evaluation and testing of a circuit pack during the design phase is achieved by connecting it to test equipment or other circuit packs using cables or a prototype backplane design. Frequently, a frame of equipment comprised of a multiplicity of shelves each having its own backplane, has been used as the interface for design testing. Another typical approach is to design a custom test fixture mounting with a specialized backplane for each circuit pack. This approach has the distinct disadvantage of being usable only with circuit packs that have the same physical characteristics and, therefore, circuit packs of a different size can not be readily evaluated without the construction of another specialized test fixture. Accordingly, known mounting assemblies for testing individual circuit packs are cumbersome and difficult to use, inefficient to make, costly to fabricate and maintain, and time-consuming since they increase circuit pack development intervals.